In multi-signal data transfer, differential signaling is sometimes used to transmit information by sending complementary signals on two paired wires/conductors, where the information is conveyed by the difference between the paired wires/conductors.
FIG. 1 illustrates a typical differential signaling system. A transmitter device 102 may include a plurality of drivers 108, each driver 108 coupled to a pair of wires/conductors 106a/106b, 106c/106d, and 106e/106f. A receiver device 104 may include a plurality of receivers 110, each receiver 110 coupled to one of the pair of wires/conductors 106a/106b, 106c/106d, and 106e/106f. A resistance R 120 may be present between each pair of wires/conductors 106a/106b, 106c/106d, and 106e/106f. The transmitter device 102 receives input bits 118, encodes them into differential signals, and transmits them to the receiver device 104 via each pair of wires/conductors 106a/106b, 106c/106d, and 106e/106f. The receiver device 104 receives the differential signals via each pair of wires/conductors 106a/106b, 106c/106d, and 106e/106f, decodes the differential signals, and provides output bits 120. In this typical differential signaling system, n wires and n/2 drivers/receivers are used and are capable of representing up to 2(n/2) states (or n/2 bits) per cycle.
FIG. 2 further illustrates the transmission of differential signals across the pair of wires/conductors 106a/106b, 106c/106d, and 106e/106f of FIG. 1. As can be appreciated, a total of eight (8) states 202 may be possible using six (6) wires under this traditional differential signaling system.
However, it would be desirable to improve on the traditional differential signaling approach to provide even more states per line using a differential signaling system while also conserving power where possible.